Source Insight does not contain a debugger for macros.
However, since macros are interpreted, you can easily figure out what’s
going on by using the “Msg” function at strategic points
in your code to output strings and variable values. See also “Msg (s)”.

To begin executing a macro statement at the current
cursor position, use the Run Macro. Just put the insertion point on
the line you want to start running at and invoke the Run Macro command.